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化学学报
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化学学报 ›› 2011, Vol. 69 ›› Issue (10): 1160-1166. 上一篇    下一篇

研究论文

一种酚类抑制剂对亚硫酸镁氧化反应动力学的影响及作用机理

汪黎东*,1,2,马永亮2,郝吉明2, 张雯娣1,袁钢2   

  1. (1华北电力大学环境科学与工程学院 保定 071003)
    (2清华大学环境科学与工程系 北京 100084)
  • 投稿日期:2010-09-29 修回日期:2010-12-03 发布日期:2011-01-26
  • 通讯作者: 汪黎东 E-mail:wld@ncepubd.edu.cn
  • 基金资助:

    国家863重点项目;教育部重点项目;中央高校基本科研业务费专项资金

Mechanism and Effect of a Phenol Inhibitor on the Oxidation Kinetics of Magnesium Sulfite

Wang Lidong*,1,2,Ma Yongliang2,Hao Jiming2,Zhang Wendi1,Yuan Gang2   

  1. (1 School of Environmental Science and Engineering, North China Electric Power University, Baoding 071003)
    (2 Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084)
  • Received:2010-09-29 Revised:2010-12-03 Published:2011-01-26
  • Contact: Li-Dong WANG E-mail:wld@ncepubd.edu.cn
  • Supported by:

    ;Fundamental Research Funds for the Central Universities

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亚硫酸镁的氧化是湿式镁法烟气脱硫过程中的重要步骤. 通过实验筛选出一种新型酚类抑制剂(T), 可显著延缓亚硫酸镁的氧化反应速率. 在接近实际工况条件下, 研究了抑制剂浓度、亚硫酸镁浓度、氧分压、pH、温度等条件对亚硫酸镁氧化速率的影响. 结果表明, 抑制剂T、溶解氧及亚硫酸镁的分级数分别为－0.25, 0.5和0, 反应的表观活化能为48.2 kJ•mol－1. 结合建立的三相反应模型, 对T抑制条件下的总反应过程进行了推断, 认为亚硫酸镁氧化的本征化学反应在贫氧区进行, 而总反应速率受氧的传质扩散过程控制. 与非抑制条件下的结果相比, T的存在降低了本征反应速率, 进而使氧的传质速率减小. 研究结果为利用抑制氧化手段实现脱硫副产物回收提供了有益参考.

关键词: 酚类抑制剂, 亚硫酸镁, 氧化, 动力学, 脱硫

Magnesium sulfite oxidation is an important step in the wet magnesia flue gas desulphurization process. In this paper, a novel phenol inhibitor, T, is selected by comparison experiments that could slow down the oxidation rate of magnesium sulfite greatly. Effects of inhibitor concentration, magnesium sulfite concentration, oxygen partial pressure, pH and temperature, on the oxidation rate were studied under the condition close to the practical. The results show that the reaction orders for inhibitor T, dissolved oxygen and magnesium sulfite are －0.25, 0.5 and 0, respectively. And the apparent activation energy is 48.2 kJ•
mol－1. Integrated with the three-phase reaction model, the general reaction process was deduced. It is concluded that the intrinsic chemical reaction takes place in the poor oxygen zone and the general reaction rate is controlled by the oxygen diffusion. Compared with the results under the uninhibited conditions, the presence of T delays the intrinsic reaction rate, resulting in the decrease of oxygen diffusion rate. Thus the result provides a useful reference for recycle of byproduct by inhibited oxidation in magnesia desulphurization.

Key words: phenol inhibitor, magnesium sulfite, oxidation, kinetics, desulphurization